FOR THOSE THAT DON'T KNOW; THE "AR" IN AR-15 STANDS FOR "ASSAULT RIFLE"; THE 15 STANDS FOR THE NUMBER OF BULLETS IT CAN HOLD; THE THING YOU SLIDE THE BULLETS DOWN INTO IS CALLED A "CLIP"; IN ORDER FOR THE BULLETS TO SLIDE UP AND DOWN IN THE CLIP THE INSIDE MUST BE SLIPPERY LIKE THE INSIDE OF A BANANA PEEL; SOME PEOPLE WILL CALL THIS A "BANANA CLIP" A 15 ROUND BANANA CLIP.